There are several avenues of acquiring NIX by participating in the NIX ecosystem.
Those include purchasing on exchanges, rewards and fees from a Ghostnode, rewards from staking your coins, becoming an LPoS Merchant and accepting NIX as payment for eCommerce transactions.
NIX is currently listed on the following exchanges:
Ghost Nodes receive rewards for securing the network. Read more in the whitepaper.
NIX is Proof of Stake and thus allows for holders of any amount to stake their coins in order to receive rewards. Refer to the Staking category:
With NIX's Leased Proof of Stake it is possible for users to lease coins to third-party merchants to stake for them. These staking providers may take a fee for their services.